Displacement measurement

Tables I and 2 show the experimental results obtained for axial and transversal displacements respectively, where % is the displacement and Xv. is the displacement measured using our experimental. setup.

Depth-sensing nanoindentation is one of the primary tools for nanomechanical mechanical properties measurements. Major advantages to this technique over AFM include (1) simultaneous measurement of force and displacement (2) perpendicular tip-sample approach and (3) well-modeled mechanics for dynamic measurements. Also, the ability to quantitatively infer contact area during force-displacement measurements provides a very useful approach to explore adhesion mechanics and models. Disadvantages relative to AFM include lower force resolution, as well as far lower spatial resolution, both from the larger tip radii employed and a lack of sample positioning and imaging capabilities provided by piezoelectric scanners. 

Mathematical techniques allow us to quantify total displacement caused by all vibrations, to convert the displacement measurements to velocity or acceleration, to separate this data into its components using FFT analysis, and to determine the amplitudes and phases of these functions. Such quantification is necessary if we are to isolate and correct abnormal vibrations in machinery. 

Displacement is the actual change in distance or position of an object relative to a reference point and is usually expressed in units of mils, 0.001 inch. For example, displacement is the actual radial or axial movement of the shaft in relation to the normal centerline usually using the machine housing as the stationary reference. Vibration data, such as shaft displacement measurements acquired using a proximity probe or displacement transducer, should always be expressed in terms of mils peak-to-peak. 

Various methods may be used for the determination of gas holdup—for example, displacement measurements and tracer experiments. Farley and Ray (F2) have described the use of gamma-radiation absorption measurement for the determination of gas holdup in a slurry reactor for the Fischer-Tropsch synthesis. 

Other, similar methods for measuring surface-surface interactions, which come under the generic heading of surface force apparatus, include the crossed-filament method. This utilizes a beam deflection technique similar to that now being used in some AFMs for the measurement of surface displacement [94]. Another technique for displacement measurement used in a similar SFA is that of a capacitance transducer. Both techniques suffer the criticism that separation is not measured at the point of interest, i.e., the gap between the two surfaces as measured in the FECO technique. 

Applied force and displacement measurements have also been used to generate force versus displacement curves (F-D plots) [99], Such information can be used to estimate the energy necessary to form a compact in the following manner ... 

Integration of displacement measurement in more and more washing machines can be expected in the future. 

Non-Contact Eddy Current Displacement Measuring System eddy current principle Micro-Epsilon eddyNCDT Series 3300... 

Optical Laser Displacement Measuring laser based triangulation principle Micro-Epsilon optoNCDT 2200... 

Inductive Potentiometric Displacement Measurement distributed electromagnetic parameters Micro-Epsilon vipSENSOR industrial use, productions plants, OEM - sensor... 

Claus, R. O. Gunther, M. F. Wang, A. Murphy, K. A., Extrinsic Fabry Perot sensor for strain and crack opening displacement measurements for 200 to 900° C, J. Smart Mater. Struct 1992, 1, 237 242... 

MZq shall not be applied simultaneously. The shaft displacement measurements shall be absolute (not relative to the baseplate). For record purposes, the vendor s test data shall include a schematic drawing of test setup, the calculated moment loads MYq and and the applied moment loads and their corresponding displacements at the drive end of the pump shaft. 

If specified, the vendor shall test to demonstrate that the pump and its baseplate assembly, anchored at foundation bolt hole locations, are in compliance with 6.3.5. The pump casing shall be subjected to moments MTc and MZc applied to either nozzle, but not both, such that the corresponding shaft displacements can be measured and recorded. MYc and MZc shall not be applied simultaneously to either nozzle. The shaft displacement measurements shall be absolute (not relative to the baseplate). For record purposes, the vendor s test data shall include a schematic drawing of test set-up, the calculated moment loads 0/Fcand MZc), and the applied moment loads and their corresponding displacements at the drive end of the pump shaft. 

Because of the force and deformation, the displacement measured by the voltage applied on the z piezo may different from the true tip-sample distance. We will denote it as the apparent displacement whenever it appears. 

The goal is to estimate the error in the final result u from the errors in measured quantities x, y, z The errors can be random or systematic. Random errors displace measurements in an arbitrary direction whereas systematic errors displace measurements in a single direction. Systematic errors shift all measurement in a systematic way so that their mean value is displaced. For example, a miscalibrated raler may yield consistently higher values of length. Random errors fluctuate from one measurement to the next. They yield results distributed about the same mean value. Random errors can be treated by statistical analysis based on repeated measurements whereas systematic errors cannot. 

Figure 6 Displacement measurement for each load level...

The ease of time-varying charge displacement, measured as the time-dependent dielectric or magnetic permittivity (or permeability), is expressed by the dielectric function e and magnetic function /x. Both e and // depend on frequency both measure the susceptibility of a material to react to electric and magnetic fields at each frequency. For succinctness, only the dielectric function and the electrical fluctuations are described in the rest of this introductory section. The full expressions are given in the application and derivation sections of Levels 2 and 3. 

Tableting machine simulators [41-48] have been developed in order to mimic tablet production systems with a very small amount of powder. Similar to eccentric tableting machines, tableting machine simulators use one pair of punches. Working only with a single pair of punches reduces the consumption of tableting materials and facilitates instrumentation for displacement measurement.

Most recently an analysis technique was developed which allows measurement of tablet temperature directly after ejection of the tablet on the machine (Figure 11) by an infrared sensor [85], The temperature signal can be directly related to force and displacement measurement. 

One method to analyze tableting data is the use of force-time or pressure-time diagrams. They are easily recordable since displacement measurement is not necessary. 

The most extensively used method to characterize the tableting process is the use of force and displacement measurements. Usually upper punch force and upper punch displacement are used. Models which relate force and displacement directly can be distinguished from those which analyze pressure and volume. 

Relation between Volume and Pressure The oldest method of this type of analysis is to establish a relation between the volume of the tablet and the force necessary to produce this volume [62, 71]. For exact description the height of the tablet is determined by displacement measurement and the accuracy of this measurement is extremely important. Further displacement measurement has to be corrected precisely for elastic deformation of the punches and the machine in order to use correct tablet heights. 

Despite this critique of the Heckel equation, the analysis of Heckel plots has been intensively used for the description of powder compression [128, 133-136], Gabaude et al. [136] stated that the analysis is quite useful when defining preconditions exactly and apply correct displacement measurement. 

---